Apparatus for performing an electrosurgical procedure

ABSTRACT

An endoscopic forceps is provided and includes a housing having a shaft that extends therefrom. An end effector assembly is operatively connected to a distal end of the shaft and includes a pair of pivotably coupled first and second jaw members. The jaw members are movable relative to one another. A drive mechanism includes a driving structure. A link assembly includes two or more links that are operably coupled to each other and the drive structure. The two or more links are operably coupled to respective ones of the first and second jaw members.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a divisional application of U.S. patent applicationSer. No. 14/887,529, filed on Oct. 20, 2015, now U.S. Pat. No.10,085,795, which is a divisional application of U.S. patent applicationSer. No. 13/113,231, filed on May 23, 2011, now U.S. Pat. No. 9,161,807,the entire contents of each of which are hereby incorporated herein byreference.

BACKGROUND Technical Field

The present disclosure relates to an apparatus for performing anelectrosurgical procedure. More particularly, the present disclosurerelates to an electrosurgical apparatus including an end effectorassembly having a pair of jaw members that provide a mechanicaladvantage at the end effector.

Description of Related Art

Electrosurgical instruments, e.g., electrosurgical forceps (open orclosed type), are well known in the medical arts and typically include ahousing, a handle assembly, a shaft and an end effector assemblyattached to a distal end of the shaft. The end effector includes jawmembers that are configured to manipulate tissue (e.g., grasp and sealtissue). Typically, the electrosurgical forceps utilizes both mechanicalclamping action and electrical energy to effect hemostasis by heatingthe tissue and blood vessels to coagulate, cauterize, seal, cut,desiccate, and/or fulgurate tissue. Typically, one or more drivingmechanisms, e.g., a drive assembly including a drive element, isutilized to cooperate with one or more components operatively associatedwith the end effector to impart movement to one or both of the jawmembers.

To facilitate moving the jaw members from an open position for graspingtissue to a closed position for clamping tissue (or vice versa) suchthat a consistent, uniform tissue effect (e.g., tissue seal) isachieved, one or more types of suitable devices may be operablyassociated with the electrosurgical forceps. For example, in someinstances, one or more cam members, e.g., a cam pin, may operably coupleto the drive element, e.g., a drive rod, wire, cable, etc., and operablycouple to a cam slot that is operably associated with one or both of thejaw members. Typically, the cam slots are operably disposed on proximalends of the jaw members. In certain instances, the proximal ends of thejaw members are configured to extend outside of the shaft profile. Inthe extended position, the proximal ends of the jaw members are commonlyreferred to as “flags.”

In certain instances, the shaft may bend or deform during the course ofan electrosurgical procedure. For example, under certain circumstances,a clinician may intentionally bend or articulate the shaft to gaindesired mechanical advantage at the surgical site. Or, under certaincircumstances, the surgical environment may cause unintentional orunwanted bending or flexing of the shaft, such as, for example, in theinstance where the shaft is a component of a catheter-basedelectrosurgical forceps. More particularly, shafts associated withcatheter-based electrosurgical forceps are typically designed tofunction with relatively small jaw members, e.g., jaw members that areconfigured to pass through openings that are 3 mm or less in diameter.Accordingly, the shaft and operative components associated therewith,e.g., a drive rod, are proportioned appropriately. That is, the shaftand drive rod are relatively small.

As can be appreciated, when the shaft is bent or deformed (eitherintentionally or unintentionally) any forces or frictional losses at thedistal end of the shaft including those caused by the “flags” extendingthrough the shaft profile and having to displace the flexible insulationmay be transferred to the drive rod, drive element, and/or a springoperably associated with the drive assembly, which, in turn, maydiminish, impede and/or prevent effective transfer of the desiredclosure force that is needed at the jaw members. Moreover, thefrictional losses may also lessen the operative life of the spring,which, in turn, ultimately lessens the operative life of theelectrosurgical instrument.

SUMMARY

The present disclosure provides an endoscopic forceps. The endoscopicforceps includes a housing having a shaft that extends therefrom anddefines a longitudinal axis therethrough. An end effector assembly isoperatively connected to a distal end of the shaft and includes a pairof first and second jaw members. The first and second jaw members arepivotably coupled to one another. The first and second jaw members aremovable relative to one another from an open position, wherein the firstand second jaw members are disposed in spaced relation relative to oneanother, to a clamping position, wherein the first and second jawmembers cooperate to grasp tissue therebetween. A drive mechanismincludes a driving structure. A link assembly includes two or more linksthat are operably coupled to each other and the driving structure. Thetwo or more links are operably coupled to respective ones of the firstand second jaw members at proximal ends thereof. The proximal ends ofthe first and second jaw members each includes a stop member that isconfigured to contact the respective one of the at least two links. Thestop members of the first and second jaw members include a generallyslanted trailing edge that is configured to contact a leading edge ofthe respective one of the at least two links as the at least two linkstransition past vertical such that the first and second jaw members arereleasably maintained in the clamping position.

The present disclosure provides endoscopic forceps. The endoscopicforceps includes a housing having a shaft that extends therefrom anddefines a longitudinal axis therethrough. The shaft has a cam operablydisposed thereon adjacent a distal end thereof. An end effector assemblyis operatively connected to a distal end of the shaft adjacent the camand includes a pair of first and second jaw members pivotably coupled toone another. One or both of the first and second jaw members are movablerelative to the other jaw member from an open or neutral position,wherein the first and second jaw members are disposed in spaced relationrelative to one another, to a clamping position, wherein the first andsecond jaw members cooperate to grasp tissue therebetween. A drivemechanism includes a driving structure. A link assembly includes two ormore links. A top portion of one of the links operably couples to abottom portion of the other link. The top and bottom portions of thelinks are operably coupled to each other and the driving structure via apivot pin. The two or more links are operably coupled to respective onesof the first and second jaw members at proximal ends thereof.

BRIEF DESCRIPTION OF THE DRAWING

Various embodiments of the present disclosure are described hereinbelowwith references to the drawings, wherein:

FIG. 1 is a side, perspective view of an endoscopic bipolar forcepsshowing an end effector assembly including jaw members according to anembodiment of the present disclosure;

FIG. 2 is a side, perspective view of the endoscopic bipolar forcepsdepicted in FIG. 1 illustrating internal components associated with ahandle assembly associated with the endoscopic bipolar forceps;

FIG. 3 is a schematic view of the jaw members depicted in FIGS. 1 and 2illustrating a distal end of a driving structure operably coupled to thejaw members;

FIG. 4 is a schematic view illustrating a distal end of the drivingstructure depicted in FIG. 3 according to another embodiment of thepresent disclosure;

FIG. 5 is a schematic view illustrating an end effector assemblyincluding jaw members according to another embodiment of the presentdisclosure;

FIG. 6 is a schematic view illustrating an end effector assemblyincluding jaw members according to yet another embodiment of the presentdisclosure;

FIG. 7 is a schematic view illustrating an end effector assemblyincluding jaw members according to still another embodiment of thepresent disclosure;

FIG. 8 is a schematic view illustrating an end effector assemblyincluding jaw members according to still yet another embodiment of thepresent disclosure;

FIG. 9 is a schematic view illustrating an end effector assemblyincluding jaw members according to yet another embodiment of the presentdisclosure;

FIG. 10 is a schematic view illustrating an end effector assemblyincluding jaw members according to still yet another embodiment of thepresent disclosure; and

FIG. 11 is a schematic view illustrating an end effector assemblyincluding jaw members according to yet another embodiment of the presentdisclosure.

DETAILED DESCRIPTION

Detailed embodiments of the present disclosure are disclosed herein;however, the disclosed embodiments are merely examples of thedisclosure, which may be embodied in various forms. Therefore, specificstructural and functional details disclosed herein are not to beinterpreted as limiting, but merely as a basis for the claims and as arepresentative basis for teaching one skilled in the art to variouslyemploy the present disclosure in virtually any appropriately detailedstructure.

In the drawings and in the descriptions that follow, the term“proximal,” as is traditional, will refer to an end which is closer tothe user, while the term “distal” will refer to an end that is fartherfrom the user.

With reference to FIGS. 1 and 2, an illustrative embodiment of anelectrosurgical apparatus, e.g., a bipolar forceps 10 (forceps 10) isshown. Forceps 10 is operatively and selectively coupled to anelectrosurgical generator (not shown) for performing an electrosurgicalprocedure. As noted above, an electrosurgical procedure may includesealing, cutting, cauterizing coagulating, desiccating, and fulguratingtissue all of which may employ RF energy. The electrosurgical generatormay be configured for monopolar and/or bipolar modes of operation andmay include or be in operative communication with a system that mayinclude one or more processors in operative communication with one ormore control modules (not shown) that are executable on the processor.The control module may be configured to instruct one or more modules totransmit electrosurgical energy, which may be in the form of a wave orsignal/pulse, via one or more cables (e.g., an electrosurgical cable310) to the forceps 10.

Forceps 10 is shown configured for use with various electrosurgicalprocedures and generally includes a housing 20, an electrosurgical cable310 that connects the forceps 10 to the electrosurgical generator, arotating assembly 80 and a trigger assembly 70. For a more detaileddescription of the rotating assembly 80, trigger assembly 70, andelectrosurgical cable 310 (including line-feed configurations and/orconnections), reference is made to commonly-owned U.S. patentapplication Ser. No. 11/595,194 filed on Nov. 9, 2006, now U.S. PatentPublication No. 2007/0173814.

With continued reference to FIGS. 1 and 2, forceps 10 includes a shaft12 that has a distal end 14 configured to mechanically engage an endeffector assembly 100 operably associated with the forceps 10 and aproximal end 16 that mechanically engages the housing 20.

A cam slot 13 of suitable configuration is positioned at the distal end4 of the shaft 12 and is configured to receive a pivot pin 111 thereinsuch that the pivot pin 111 may translate therein (FIGS. 1-4). In theillustrated embodiment, the cam slot 13 is defined through the shaft 12.

A resilient member in the form of a compression spring 15 is provided atthe distal 14 end of the shaft 12. In particular, the spring 15 isgrounded to an internal wall of the shaft 12 and couples to the pivotpin 111 via a one or more suitable coupling methods (FIGS. 3 and 4). Inthe illustrated embodiment, a spring coupler 17 operably couples thepivot pin 111 to the spring 15.

Handle assembly 30 includes a fixed handle 50 and movable handle 40(FIGS. 1 and 2). In one particular embodiment, fixed handle 50 isintegrally associated with housing 20. Movable handle 40 is movablerelative to fixed handle 50 for effecting movement of one or morecomponents, e.g., driving structure 133, operably associated with adrive mechanism 130 (FIGS. 2 and 3). Handle assembly 30 includingmovable handle 40 may be configured such that proximal movement of themovable handle 40 “pushes” the driving structure 133, which, in turn,imparts movement of the jaw members 110 and 120 from a normally openposition (FIG. 1) to closed or clamping position (FIGS. 2 and 3).Alternatively, handle assembly 30 including movable handle 40 and drivemechanism 130 may be configured such that proximal movement of themovable handle 40 “pulls” the driving structure 133, which, in turn,imparts movement of the jaw members 110 and 120 from a normally an openposition (FIG. 1) to a closed position, wherein the jaw members 110 and120 are configured to grasp tissue therebetween.

Drive mechanism 130 is in operative communication with movable handle 40(see FIGS. 1 and 2) for imparting movement of one or, in some instances,both of the jaw members 110, 120 of end effector assembly 100. Moreparticularly, one or more suitable mechanical interfaces, e.g., alinkage interface, gear interface, or combination thereof operablycouples the movable handle 40 to the drive mechanism 130. In theembodiment illustrated in FIGS. 1-3, proximal movement of the movablehandle 40 moves the jaw members 110 and 120 toward each other from thenormally open position to the clamping position.

Driving structure 133 is configured such that distal movement thereofcauses the jaw members 110 and 120 to move from the open position(FIG. 1) to the clamping position (FIGS. 2 and 3) and vice versa. Tothis end, driving structure 133 may be any suitable driving structure ormechanism including but not limited to a wire, rod, cable, band, etc. Inthe illustrated embodiment, driving structure 133 is a substantiallyflexible drive rod 133 of suitable proportion that is dimensioned totranslate within the shaft 12 (see FIGS. 1-3). Drive rod 133 isdimensioned such that the drive rod 133 does not to “buckle” or “kink”when the drive rod 133 is moved distally and/or proximally within theshaft 12. Drive rod 133 includes a proximal end (not explicitly shown)that is in operative communication with the movable handle 40.

With reference to FIG. 3, a distal end 135 of the drive rod 133 operablycouples to the end effector 100 and/or jaw members 110 and 120. Moreparticularly, and in the embodiment illustrated in FIG. 3, a pivot pin21 a (or rivet, fastener, living-hinge or the like) operably couples thedistal end 135 of the drive rod 133 to a link assembly 19.

Link assembly 19 is an over-the-center link type and includes two ormore links. In the embodiment illustrated in FIG. 3, link assembly 19includes two links 19 a and 19 b. Links 19 a and 19 b are pivotablycoupled to each other via one or more suitable coupling methods. Moreparticularly, pivot pin 21 a operably couples the distal end 135 of thedrive rod 133 to a top portion of the link 19 a and a bottom portion ofthe link 19 b. Link assembly 19 including links 19 a and 19 b serves tolatch the jaw members 110 and 120 in the closed or clamping positionwhen the links 19 a and 19 b and/or pivot pin 21 a moves past a centerpoint of the link assembly 19. That is, as the links 19 a and 19 btransition past vertical, the links 19 a and 19 b are configured tocontact and/or releasably engage the jaw members 110 and 120 (orcomponent associated therewith) of the end effector such that the jawmembers 110 and 120 remain in the closed or clamping position, describedin greater detail below. As can be appreciated, having the link assembly19 serve as a latch may eliminate the need for a separate latchingdevice in the housing 20 and/or handle assembly 30 as is typicallyutilized with conventional forceps. Moreover, the link assembly 19provides an additional mechanical advantage when closing the jaw members110 and 120 at the beginning of a closing or clamping stroke (i.e., whenthe movable handle 40 is moved proximally). That is, due to thegeometries of the links 19 a and 19 b, the force at the jaw members 110and 120 is controlled by the geometry and stiffness of the links 19 aand 19 b and/or the jaw members 110 and 120 (or operative componentsassociated therewith).

A top portion of the link 19 b operably couples to jaw member 120. Moreparticularly, a pivot pin 21 b operably couples the top portion of thelink 19 b to a proximal end 127 a of the jaw member 120 (FIG. 3).Likewise, a pivot pin 21 c operably couples a top portion of the link 19a to the jaw member 110 (FIG. 3).

End effector assembly 100 is illustrated operably disposed at the distalend 14 of the shaft 12 (FIGS. 1-3). End effector assembly 100 includesopposing jaw members 110 and 120 that mutually cooperate to grasp, sealand, in some cases, divide large tubular vessels and large vasculartissues. As noted above, in the illustrated embodiment, jaw members 110and 120 are movable relative to each other. Jaw members 110, 120 areoperatively and pivotably coupled to each other via a pivot pin 111 andare located adjacent the distal end 14 of shaft 12. Electricallyconductive seal plates 118 and 128 are operably supported on and securedto respective distal ends 117 b and 127 b of jaw housings 117 and 127.Jaw members 110 and 120 including respective jaw housings 117 and 127,and operative components associated therewith, may be formed from anysuitable material, including but not limited to metal, metal alloys,plastic, plastic composites, ceramics, ceramic composites, and so forth.

Jaw housing 127 and 117 of the respective jaw members 110 and 120 aresubstantially identical to each other. In view thereof, the operativefeatures of jaw housing 127 are described in detail, and only thosefeatures that are unique to jaw member 110 are described hereinafter.

With continued reference to FIG. 3, an embodiment of jaw housing 127 isillustrated. Jaw housing 127 includes distal end 127 b that isconfigured to operably support seal plate 128 and proximal end 127 athat operably couples to the distal end 14 of shaft 12 and to the topportion of the link 19 b. Proximal end 127 a includes a generallyelongated configuration, and is dimensioned to move, e.g., pivot, withinthe shaft 12 from the open position to the closed or clamping position.Pivot pin 111 couples the first and second jaw members 110 and 120,respectively (FIG. 3) for pivotal movement relative to one another.

Proximal end 127 a serves as a beam that, in concert with the links 19 aand 19 b, regulates a clamping force at the jaw members 110 and 120 whenthe links 19 a and 19 b transition past vertical and the jaw members 110and 120 are in the clamping position with tissue disposed therebetween.Proximal end 127 a may be relatively resilient, or in some instances,may be substantially rigid. The resiliency, or lack thereof, may bevaried based on a specific surgical procedure, manufacturer and/or userpreference, etc. In the embodiment illustrated in FIG. 3, proximal end127 a is relatively resilient.

One or more stop members 23 b (one stop member 23 b is illustrated inthe drawings) are operably disposed on the proximal end 127 a of the jawhousing 127. Stop member 23 b is configured to contact and/or releasablyengage the link 19 b of the link assembly 19 when the links 19 a and 19b have transitioned past vertical. More specifically, stop member 23 bincludes an angled trailing edge 25 that is configured to contact aleading edge 27 of the link 19 b. This contact between the angledtrailing edge 25 of the stop 23 b and the leading edge 27 of the link 19b facilitates “latching” jaw member 120 in the clamping position. Thatis, when the angled trailing edge 25 contacts the leading edge 27, thelinks 19 a and 19 b including pivot pin 21 a are prevented from movingdistally.

Jaw housing 117 of jaw member 110 includes components similar to that ofthe components associated with jaw housing 127 of jaw member 120. Moreparticularly, jaw housing 117 includes proximal end 117 a that functionssimilarly to that of proximal end 127 a of jaw housing 127 a. Proximalend 117 a of the jaw member 110 includes a stop member 23 a having anangled trailing edge 31 that is configured to contact a correspondingleading edge 35 of the link 19 a. Stop 23 a functions in a mannersubstantially similar to that of stop 23 b.

The jaw members 110 and 120 may be coupled to each other via anysuitable coupling methods. In the illustrated embodiment, an opening 108is defined in and extends through each jaw housing 117 and 127 and isconfigured to receive pivot pin 111. Opening 108 is shown engaged withpivot pin 111 and as such is not explicitly visible.

In an assembled configuration, pivot pin 111 is positioned within theopenings associated with each of the jaw members 110 and 120. Onceassembled, the jaw members 120 and/or jaw member 110 may be pivotablysupported at the distal end 14 of the shaft 12 by known methods, suchas, for example, by the method described in commonly-owned U.S. Pat. No.7,597,693 to Garrison filed on Jun. 13, 2003.

In use, jaw members 110 and 120 are, initially, in the open position(FIG. 1). Tissue is positioned between the jaw members 110 and 120. Oncetissue is positioned between the jaw members 110 and 120, movable handle40 is moved proximally (FIG. 2), which, in turn, causes the drive rod133 to move distally. Distal movement of drive rod 133 causes the links19 a and 19 b to pivot, i.e., in respective clockwise andcounterclockwise directions, about pivot pins 21 a-21 c and movedistally. As links 19 a and 19 b move distally, the pivot pin 111 movesdistally against the bias of the spring 15 and the jaw members 110 and120 move toward one another and to the clamping position. Ultimately,links 19 a and 19 b transition past vertical and the respective leadingedges 35 and 27 of links 19 a and 19 b contact respective trailing edges31 and 25 of stops 23 a and 23 b. Contact between the leading edges 35and 27 and trailing edges 31 and 25 “latches” the jaw members 110 and120 in the clamping position. Thereafter, tissue is electrosurgicallytreated, e.g., tissue is sealed. Subsequently, movable handle 40 isreleased and pivot pin 15 moves proximally and the jaw members 110 and120 move away from one another and back to the open or neutral position.

The unique configuration of the link assembly 19 including links 19 aand 19 b and proximal ends 117 a and 127 a improves the opening andclosing angles typically associated with known forceps jaw designs.Moreover, the unique configuration of the link assembly 19 includinglinks 19 a and 19 b and proximal ends 117 a and 127 a eliminates theneed of having the proximal ends 117 a and 127 a (“flags”) extend pastthe profile of the shaft 12.

With reference to FIG. 4, in certain embodiments, a cam member 41 may beoperably coupled to the shaft 12 and operably disposed adjacent the endeffector 100. For illustrative purposes, the stop members 23 a and 23 bare not shown in FIG. 4. The cam member 41 is configured to cam thelinks 19 a and 19 b toward a horizontal position and each other as thedrive rod 133 is moved proximally. To this end, the cam member 41includes an opening 43 that is configured to receive the drive rod 133therethrough. Cam member 41 includes slanted leading edges 45 and 47that are configured to contact respective trailing edges 49 and 51 oflinks 19 a and 19 b such that the jaw members 110 and 120 remain in theopen or neutral position.

In use and with movable handle 40 in a distal position (see FIG. 1 forexample), the trailing edges 49 and 51 of links 19 a and 19 b contactthe leading edges 45 and 47 of the cam member 41. This contact betweentrailing edges 49, 51 and the leading edges 45, 47 force the links 19 aand 19 b to pivot about the pivot pin 21 a and maintain the jaw members110 and 120 in the open or neutral position.

From the foregoing and with reference to the various figure drawings,those skilled in the art will appreciate that certain modifications canalso be made to the present disclosure without departing from the scopeof the same. For example, it is contemplated that in certain instancesone or more resilient members, e.g., a compression spring 200, may beoperably associated with or coupled to either the link assembly 19including links 19 a and 19 b and/or one or both of the jaw members 110and 120 (see FIG. 5, for example). More particularly, a compressionspring 200 may be coupled to the pivot pin 21 a and the pivot pin 111 byone or more suitable coupling methods, e.g., soldering. In thisinstance, the spring 200 may be configured to provide a clamping forceor seal force in the range of about 3 kg/cm² to about 16 kg/cm² betweenthe jaw members 110 and 120 when the jaw members 110 and 120 are in theclamping position.

With reference to FIG. 5, an end effector assembly 300 is illustrated.End effector assembly 300 is substantially similar to end effector 100.As a result thereof, only those features unique to end effector 300 aredescribed herein. In the embodiment illustrated in FIG. 5, the cammember 41 is configured to translate along the longitudinal axis “A-A”(see FIG. 5). More particularly, cam member 41 is movable from aproximal position that corresponds to the jaw members 110 and 120 beingin the clamping position to a distal position that corresponds to thejaw members being in the open position.

Unlike the previously described embodiments, the cam member 41 operablycouples (via one or more suitable coupling methods, e.g., soldering) toa bifurcated distal end 135 having bifurcated ends 135 a and 135 b andthe link assembly 19 is fixedly attached to an internal frame of theshaft 12. Operation of the forceps 10 with the end effector 200 issubstantially similar to that of end effector 100. A distinguishingfeature of the operation of the forceps 10 with the end effector 300when compared to the end effector 100, is that the jaw members 100 and200 are biased in the clamping configuration by the spring 200 thatprovides a clamping force or seal force in the range of about 3 kg/cm²to about 16 kg/cm² between the jaw members 110 and 120. Moreover, whenmovable handle 40 is moved proximally, cam member 41 moves distally andcontacts the links 19 a and 19 b, which, in turn, causes the links 19 aand 19 b to pivot about the pivot pin 21 a and the jaw members 110 and120 to move away from each other to the open position against the biasof the spring 200.

With reference to FIG. 6, an end effector assembly 400 is illustrated.End effector assembly 400 is substantially similar to end effectors 100and 300. As a result thereof, only those features unique to end effector400 are described herein. In the embodiment illustrated in FIG. 6, a cammember 410 includes two generally arcuate slots 46 a and 46 b thatrespectively couple to pivot pins 21 c and 21 b of the links 19 a and 19b (see FIG. 6). Operation of the forceps 10 with the end effector 400 issubstantially similar to that of end effector 300. However, unlike cammember 41, distal movement of the cam member 410 causes the pivot pins21 c and 21 b to translate distally within the arcuate cam slots 46 aand 46 b, respectively, which, in turn, causes the jaw members 110 and120 to move away from each other to the open position against the biasof the spring 200.

With reference to FIG. 7, an end effector assembly 500 is illustrated.End effector assembly 500 is substantially similar to end effectors 100and 300. As a result thereof, only those features unique to end effector500 are described herein.

The distal end 135 of the driving structure 133 is bifurcated or splitwith two legs or branches 135 a and 135 b that couple to respectiveresilient members 200 a and 200 b.

Resilient members 200 a and 200 b may be any suitable type of resilientmember including but not limited to: springs selected from the groupconsisting of coil, leaf and tension; gas or fluid pistons; andelastomers or other compliant materials.

A proximal end of the resilient member 200 a operably couples to thebranch 135 a of the driving structure 133 by any of the aforementionedcoupling methods (e.g., soldering, welding, or solid joints) and adistal end of the resilient member 200 a operably couples (e.g., also bysoldering) to a movable cam member 510 (cam member 510). Likewise, aproximal end of the resilient member 200 b operably couples, e.g., viasoldering, to the branch 135 b of the driving structure 133 and a distalend of the resilient member 200 b operably couples (e.g., also bysoldering) to the pivot pin 21 a of the link assembly 19. To facilitatemoving cam member 510, the resilient members 200 a and 200 b aredisposed in different horizontal planes from each other. Moreparticularly, resilient member 200 a is located above the resilientmember 200 b.

Unlike cam member 410, a cam member 510 includes two slanted or angledcam slots 510 a and 510 b that are configured to house respectivestationary cam pins 511 a and 511 b that are operably coupled to the jawmembers 120 and 110, respectively. Cam member 510 is movable along thelongitudinal axis “A-A.” In certain embodiments, the cam slots 510 a and510 b may be in the jaw members 110 and 120 and the cam pins 511 a and511 b may be attached to the cam member 510.

In use, proximal movement of the movable handle 40 causes the drivingstructure 133 including the bifurcated distal end 135 to move distally,thus, moving the cam member 510 including the cam slots 510 a and 510 bdistally, which, in turn, cams the cam pins 511 a and 511 b causing thejaw members 110 and 120 to move toward each other to the clampingposition (FIG. 7). Distal motion of movable handle 40 causes the drivingstructure 133 including the bifurcated distal end 135 to moveproximally, thus, moving the cam member 510 including the cam slots 510a and 510 b proximally, which, in turn, cams the cam pins 511 a and 511b causing the jaw members 110 and 120 to move away from each other tothe open position.

With reference to FIG. 8, an end effector assembly 600 is illustrated.End effector assembly 600 is substantially similar to end effector 500.As a result thereof, only those features unique to end effector 600 aredescribed herein.

Unlike the previously described jaw members, the jaw members 110 and 120illustrated in FIG. 8 include respective proximal ends 117 a and 127 athat are “offset” from the respective distal ends 117 b and 127 b.

In the embodiment illustrated in FIG. 8, the cam pin 21 b operablycouples the link 19 b, the cam slot 510 a and the proximal end 117 a ofthe jaw member 110 to each other. Likewise, the cam pin 21 c operablycouples the link 19 a, the cam slot 510 b and the proximal end 127 a ofthe jaw member 120 to each other.

In use, proximal movement of the movable handle 40 causes the drivingstructure 133 including the bifurcated distal end 135 to move distally,thus, moving the cam member 510 including the cam slots 510 a and 510 bdistally, which, in turn, cams the cam pins 511 a and 511 b causing thejaw members 110 and 120 to move away from each other to the openposition (FIG. 8). Distal motion of movable handle 40 causes the drivingstructure 133 including the bifurcated distal end 135 to moveproximally, thus, moving the cam member 510 including the cam slots 510a and 510 b proximally, which, in turn, cams the cam pins 511 a and 511b causing the jaw members 110 and 120 to toward each other to the closedposition.

With reference to FIG. 9, an end effector assembly 700 is illustrated.End effector assembly 700 is substantially similar to end effector 600.As a result thereof, only those features unique to end effector 700 aredescribed herein.

In the embodiment illustrated in FIG. 9, the cam pin 21 b operablycouples the link 19 b, the cam slot 510 a and the proximal end 127 a ofthe jaw member 120 to each other. Likewise, the cam pin 21 c operablycouples the link 19 a, the cam slot 510 b and the proximal end 117 a ofthe jaw member 110 to each other.

The driving structure 133 does not include a bifurcated distal end 135.Accordingly, unlike the resilient member 200 a that includes a proximalend that operably couples to the branch 135 a of the driving structure133, a proximal end of the resilient member 200 a′ is operably coupledto the pivot pin 21 a (FIG. 9). Moreover, the spring 200 a′ is disposedin the same horizontal plane as the spring 200 b.

In use, proximal movement of the movable handle 40 causes the drivingstructure 133 to move distally, thus, moving the cam member 510including the cam slots 510 a and 510 b distally, which, in turn, camsthe pivot pins 21 b and 21 c causing the jaw members 110 and 120 to movetoward each other to the clamping position (FIG. 9). Distal motion ofmovable handle 40 causes the driving structure 133 to move proximally,thus, moving the cam member 510 including the cam slots 510 a and 510 bproximally, which, in turn, cams the pivot pins 21 b and 21 c causingthe jaw members 110 and 120 to move away from each other to the openposition.

With reference to FIG. 10, an end effector assembly 800 is illustrated.End effector assembly 800 is substantially similar to end effector 700.As a result thereof, only those features unique to end effector 800 aredescribed herein.

A support structure 801 of suitable proportion is operably disposedadjacent the end effector 800. Support structure 801 is configured tocouple to one or more resilient members 200 a″.

In the embodiment illustrated in FIG. 10 two resilient members 200 a″are illustrated. Each resilient member 200 a″ includes proximal endsthat couple to a distal end of the cam member 510 and distal ends thatoperably couple to the support structure 801.

A third resilient member 200 b′ includes a proximal end that operablycouples to the pivot pin 21 a and a distal end that operably couples tothe support structure 801.

In use, proximal movement of the movable handle 40 causes the drivingstructure 133 to move distally, thus, moving the cam member 510including the cam slots 510 a and 510 b distally, which, in turn, camsthe pivot pins 21 b and 21 c causing the jaw members 110 and 120 to movetoward each other to the clamping position (FIG. 10). Distal motion ofmovable handle 40 causes the driving structure 133 to move proximally,thus, moving the cam member 510 including the cam slots 510 a and 510 bproximally, which, in turn, cams the pivot pins 21 b and 21 c causingthe jaw members 110 and 120 to move away from each other to the openposition.

With reference to FIG. 11, an end effector assembly 900 is illustrated.End effector assembly 900 is substantially similar to end effectors 500and 600. As a result thereof, only those features unique to end effector900 are described herein.

A resilient member 200 c includes a distal end that operably couples toa cam pin 21 d that is operably coupled to a pair of cam slots 127 c and117 c that are disposed on respective jaw members 120 and 110 atproximal ends 127 a and 117 a thereof.

In use, proximal movement of the movable handle 40 causes the drivingstructure 133 including bifurcated distal end 135 to move proximally,thus, moving the cam pin 21 d proximally within the cam slots 127 c and117 c, which, in turn, causes the jaw members 110 and 120 to move towardeach other to the clamping position (FIG. 11). Distal motion of movablehandle 40 causes the driving structure 133 including the bifurcateddistal end 135 to move distally, thus, moving the cam pin 21 d distallywithin the including the cam slots 127 c and 117 c, which, in turn,causes the jaw members 110 and 120 to move away from each other to theopen position.

While several embodiments of the disclosure have been shown in thedrawings, it is not intended that the disclosure be limited thereto, asit is intended that the disclosure be as broad in scope as the art willallow and that the specification be read likewise. Therefore, the abovedescription should not be construed as limiting, but merely asexemplifications of particular embodiments. Those skilled in the artwill envision other modifications within the scope and spirit of theclaims appended hereto.

What is claimed is:
 1. A surgical instrument, comprising: a shaft; anend effector assembly disposed at a distal end portion of the shaft, theend effector assembly including first and second jaw members pivotablycoupled to the shaft about a pivot such that at least one of the firstor second jaw members is movable relative to the shaft and the other ofthe first or second jaw members between an open position, wherein thefirst and second jaw members are disposed in spaced relation relative toone another, and a closed position, wherein the first and second jawmembers cooperate to grasp tissue therebetween; a driving structuredisposed within the shaft and configured for translation relative to theshaft; a linkage assembly operably coupled between the driving structureand the first and second jaw members such that translation of thedriving structure relative to the shaft moves the at least one of thefirst or second jaw members between the open position and the closedposition, the linkage assembly defining a leading edge; at least onestop member positioned in the shaft, the at least one stop memberconfigured to contact the leading edge of the linkage assembly toreleasably lock the at least one of the first or second jaw members inthe closed position; and a spring disposed between the pivot and thedriving structure, the spring configured to bias the at least one of thefirst or second jaw members.
 2. The surgical instrument according toclaim 1, wherein the spring is configured to bias the at least one ofthe first or second jaw members towards the open position.
 3. Thesurgical instrument according to claim 1, wherein the spring isconfigured to bias the at least one of the first or second jaw memberstowards the closed position to provide a closure force between the firstand second jaw members.
 4. The surgical instrument according to claim 3,wherein the closure force is in a range of about 3 kg/cm² to about 16kg/cm².
 5. The surgical instrument according to claim 1, wherein each ofthe first and second jaw members is pivotable relative to the shaft andthe other of the first and second jaw members between the open andclosed positions.
 6. The surgical instrument according to claim 1,wherein the driving structure includes at least one of: a rod, a cable,a wire, or a band.
 7. The surgical instrument according to claim 1,wherein the spring includes a proximal end fixed relative to the shaftand a distal end movable relative to the shaft.
 8. The surgicalinstrument according to claim 1, wherein the spring includes a distalend fixed relative to the shaft and a proximal end movable relative tothe shaft.
 9. The surgical instrument according to claim 1, furthercomprising a housing, wherein the shaft extends distally from thehousing.
 10. The surgical instrument according to claim 9, furthercomprising a movable handle operably associated with the drivingstructure, the movable handle movable relative to the housing totranslate the driving structure relative to the shaft.
 11. The surgicalinstrument according to claim 1, wherein the linkage assembly includesfirst and second links.
 12. The surgical instrument according to claim11, wherein the first link is operably coupled between the drivingstructure and the first jaw member, and wherein the second link isoperably coupled between the driving structure and the second jawmember.
 13. The surgical instrument according to claim 12, wherein thefirst and second links are operably coupled to one another and thedriving structure at proximal end portions of the first and secondlinks.
 14. The surgical instrument according to claim 1, wherein thelinkage assembly is disposed proximally of the spring.
 15. The surgicalinstrument according to claim 1, wherein each of the first and secondjaw members includes an opposed electrically conductive tissuecontacting surface.